List of Excipients in Branded Drug KETALAR

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Henry Schein Inc	KETALAR	ketamine hydrochloride	0404-9880	BENZETHONIUM CHLORIDE
Henry Schein Inc	KETALAR	ketamine hydrochloride	0404-9880	SODIUM CHLORIDE
Par Health USA LLC	KETALAR	ketamine hydrochloride	42023-113	BENZETHONIUM CHLORIDE

Ketalar Excipient Strategy, Patent Position, and Commercial Opportunities

Last updated: September 16, 2026

Ketalar is an injectable ketamine hydrochloride product with a simple, mature formulation. Its commercial value lies less in composition-of-matter exclusivity and more in supply reliability, preservative strategy, ready-to-use presentations, container-closure performance, and regulatory execution. The branded product has no meaningful remaining FDA exclusivity, and generic competition is established. New entrants must compete on manufacturing reliability, presentation, shortage mitigation, and differentiated delivery formats.

What is the Ketalar formulation and which excipients does it contain?

Ketalar is an aqueous injection containing ketamine hydrochloride, equivalent to ketamine base at 10 mg/mL, 50 mg/mL, or 100 mg/mL. The labeled preservative is benzethonium chloride at 0.1 mg/mL. The formulation uses water for injection, with hydrochloric acid used for pH adjustment. The labeled pH range is approximately 3.5 to 5.5. [1]

Product characteristic	Ketalar profile
Active ingredient	Ketamine hydrochloride
Dosage form	Sterile injectable solution
Strengths	10 mg/mL, 50 mg/mL, 100 mg/mL
Route	Intravenous or intramuscular injection
Preservative	Benzethonium chloride, 0.1 mg/mL
Primary vehicle	Water for injection
pH control	Hydrochloric acid
Controlled-substance status	Schedule III
Original FDA approval	1970
Reference product NDA	NDA 016812
Current exclusivity	No meaningful remaining reference-product exclusivity

The formulation is intentionally low in excipient complexity. That reduces formulation-development risk but leaves limited room for conventional excipient-based differentiation in the same injectable presentation.

What role does benzethonium chloride play in Ketalar?

Benzethonium chloride functions as an antimicrobial preservative in the multidose injectable presentation. It supports repeated withdrawals from a vial but creates several development and commercial considerations:

• Preservative exposure may be undesirable in some patient populations or clinical settings.
• Compatibility with elastomeric closures and other container components requires evaluation.
• Preservative-free positioning can support single-dose or ready-to-use presentations.
• A preservative change can affect regulatory classification, stability requirements, labeling, and container-closure specifications.

A preservative-free ketamine injection would not automatically qualify as a superior product. The commercial case would depend on a clinically relevant use setting, such as anesthesia workflows, procedural sedation, emergency medicine, or institutional policies favoring single-dose presentations.

What patents protect Ketalar and when does ketamine lose exclusivity?

Ketamine is an old active pharmaceutical ingredient. The original compound and basic injectable technology are long outside their patent terms. Ketalar has no meaningful current composition-of-matter or primary product patent protection.

The FDA Orange Book listing for Ketalar’s reference product, NDA 016812, does not provide a current patent barrier comparable to those protecting recently approved drugs. [2] The product’s commercial exclusivity ended decades ago.

Exclusivity category	Ketalar status
New chemical entity exclusivity	Expired
Original compound patent	Expired
Injectable formulation patent barrier	No material current barrier identified
Method-of-use exclusivity	No current Orange Book barrier identified
Orphan-drug exclusivity	Not applicable to Ketalar
Pediatric exclusivity	No current period
Orange Book patent litigation exposure	No active listed-patent pathway identified

What is the Orange Book status of Ketalar?

Ketalar is listed as an approved drug product associated with NDA 016812. Its active-ingredient and dosage-form profile permits generic competition through abbreviated new drug applications, subject to FDA requirements for pharmaceutical equivalence, bioequivalence where applicable, sterility, stability, manufacturing controls, and labeling.

The absence of a current Orange Book patent barrier means that a generic applicant generally does not need to overcome a live patent through a Paragraph IV certification. A Paragraph III or Paragraph IV strategy would be relevant only if a later-listed patent became associated with the reference product.

How many patents cover Ketalar?

No material active patent estate currently protects the core Ketalar injectable formulation. The relevant intellectual-property risk is therefore more likely to arise from later-developed products than from Ketalar itself.

Potentially relevant patent categories include:

1. Preservative-free ketamine injection formulations.
2. Premixed intravenous bags or syringes.
3. Extended-stability formulations.
4. Alternative buffers or tonicity systems.
5. Intranasal, buccal, sublingual, transdermal, or inhaled ketamine delivery.
6. Combination products and method-of-use claims.
7. Device-enabled administration systems.
8. Manufacturing processes that improve impurity control or shelf life.

These later patents would generally protect a particular formulation, delivery system, process, or clinical use. They would not restore exclusivity to conventional ketamine hydrochloride injection.

What excipient strategies create commercial opportunities for ketamine products?

The strongest opportunities are operational and presentation-based rather than based on adding complex excipients.

Preservative-free single-dose ketamine

A preservative-free formulation could target hospitals that prefer single-dose containers for infection-control or patient-exposure reasons. The product could be supplied in:

• Single-dose vials.
• Prefilled syringes.
• Ready-to-use syringes for procedural settings.
• Small-volume bags for controlled infusion.

The development burden would include sterility assurance, extractables and leachables, container-closure integrity, particulate control, in-use stability, and compatibility with common administration systems.

A preservative-free product may require a different package configuration and labeling strategy. Removing benzethonium chloride can also alter the formulation’s microbiological risk profile, making aseptic processing and container design commercially important.

Ready-to-use intravenous presentations

Hospitals incur labor and medication-error costs when clinicians dilute or prepare injectable drugs at the point of use. A ready-to-use ketamine product could compete through workflow efficiency rather than active-ingredient differentiation.

Potential presentations include:

Presentation	Commercial rationale	Key technical issue
Prefilled syringe	Faster emergency and procedural administration	Syringe compatibility and dose accuracy
Premixed IV bag	Reduced preparation burden	Stability, adsorption, and bag compatibility
Unit-dose vial	Infection-control and inventory control	Packaging cost
Pharmacy bulk package	High-volume institutional use	Multidose handling and labeling
Concentration-specific syringe	Reduced dilution errors	Human-factors validation

The most attractive presentation will depend on clinical setting. Emergency departments may value prefilled syringes, while operating rooms and infusion environments may prefer larger-volume containers or premixed solutions.

Excipient systems for stability and compatibility

Ketamine injection products must maintain chemical stability, physical clarity, sterility, and dose uniformity. A new excipient system could be used to address:

• pH-related degradation.
• Container adsorption.
• Precipitation after dilution.
• Compatibility with infusion materials.
• Photostability.
• Extended in-use or post-dilution stability.

The commercial value of a new buffer or stabilizer is limited unless it produces a measurable advantage, such as longer shelf life, broader dilution compatibility, reduced impurity formation, or improved storage conditions.

Alternative delivery routes

Excipient innovation has greater potential outside the conventional injectable product. Intranasal and transmucosal dosage forms may require mucoadhesive polymers, permeation enhancers, tonicity agents, buffers, and preservatives. Those formulations can support new patent claims, but they face higher clinical and regulatory risk.

Esketamine nasal spray, marketed as Spravato by Johnson & Johnson, is a separate product based on the S-enantiomer of ketamine and is not a reformulation of Ketalar. Its FDA approval for treatment-resistant depression and depressive symptoms in adults with major depressive disorder and acute suicidal ideation or behavior relies on a different clinical, formulation, and regulatory profile. [3]

What FDA pathways apply to new Ketalar formulations?

ANDA pathway for conventional generic injections

A conventional generic ketamine hydrochloride injection would typically use the 505(j) abbreviated new drug application pathway. The applicant must demonstrate pharmaceutical equivalence and comply with FDA requirements for:

• Strength and dosage form.
• Active ingredient and route of administration.
• Sterility and aseptic processing.
• Stability and shelf life.
• Impurity profile.
• Container-closure integrity.
• Labeling.
• Manufacturing controls.

A generic product can use different inactive ingredients if the formulation remains acceptable under FDA standards and does not create safety or effectiveness concerns.

505(b)(2) pathway for differentiated products

A preservative-free product, novel concentration, new delivery system, or materially different formulation may require a 505(b)(2) application rather than an ANDA. The 505(b)(2) route can rely partly on FDA findings for an approved product while supporting changes with new information.

The pathway is particularly relevant where the sponsor claims a benefit from:

• A new dosage form.
• A different route of administration.
• A new excipient system.
• A new concentration or container.
• A new clinical use.
• Improved administration or handling.

The regulatory advantage must be weighed against the need for clinical bridging, additional safety data, human-factors work, and possible patent or exclusivity issues tied to the relied-upon reference product.

Which companies compete in the ketamine injection market?

Ketamine injection is supplied by multiple generic manufacturers and contract manufacturing networks. The competitive field has included Pfizer-related manufacturing operations through Hospira, Hikma, Fresenius Kabi, and other injectable-drug suppliers, depending on product strength, presentation, and market availability. Product availability changes by facility, strength, and time period. [4]

The reference product has limited ability to command a substantial premium solely through branding. Hospitals generally evaluate suppliers on:

• Supply continuity.
• Shortage performance.
• Contract pricing.
• Available concentrations.
• Package sizes.
• Sterility history.
• Back-order frequency.
• Distribution coverage.
• Controlled-substance compliance.

How does Ketalar compare with generic ketamine injections?

Factor	Ketalar	Generic ketamine injection
Core active ingredient	Ketamine hydrochloride	Ketamine hydrochloride
Patent protection	No material current barrier	Same market access environment
Preservative strategy	Benzethonium chloride in labeled formulation	May match or vary within FDA limits
Brand premium	Limited in hospital procurement	Usually price-driven
Differentiation	Brand recognition and reference status	Supply, price, packaging, and service
Regulatory route	Approved NDA	ANDA or, for differentiated products, 505(b)(2)
Main commercial risk	Generic substitution and procurement pressure	Shortage, compliance, and margin compression

What patent litigation and Paragraph IV risks affect ketamine products?

Conventional ketamine injection has a low Paragraph IV risk because the core product is old and lacks a meaningful current patent estate. A new ketamine product can create a different risk profile if it relies on:

• A patented nasal formulation.
• A protected clinical indication.
• A device or administration method.
• A proprietary excipient combination.
• A patented manufacturing process.
• A later-approved reference product with unexpired patents.

No current settlement agreement is material to the conventional Ketalar injectable market because no significant Orange Book patent dispute defines access to the basic product.

For a new entrant, the more important diligence question is whether the proposed product will be carved out from protected uses or whether its label will overlap with method-of-use claims covering a later ketamine formulation.

What manufacturing and excipient barriers limit market entry?

Ketamine injection is chemically straightforward but operationally demanding. The main barriers are:

Controlled-substance manufacturing

Ketamine is a Schedule III controlled substance in the United States. Manufacturers must maintain DEA registration, controlled-substance security, inventory reconciliation, records, distribution controls, and diversion-prevention systems. [5]

Sterile injectable production

The product requires validated aseptic processing or terminal sterilization where technically feasible. Critical controls include:

• Bioburden and endotoxin control.
• Media fills.
• Container-closure integrity.
• Particulate inspection.
• Environmental monitoring.
• Validated sterilization or aseptic filling.
• Stability-indicating analytical methods.

Container-closure compatibility

Benzethonium chloride, ketamine, and the acidic aqueous environment must be evaluated with vial glass, rubber stoppers, syringe components, plastic bags, and administration sets. Extractables and leachables may become more important in prefilled and premixed products than in conventional vials.

Supply-chain resilience

Hospital customers may switch suppliers quickly during shortages. A new manufacturer with redundant API sourcing, multiple fill-finish sites, and a strong quality system can gain share even without formulation patents.

What is the revenue exposure and commercial upside?

Pfizer does not separately disclose Ketalar revenue in public financial reporting. Revenue exposure is therefore not reliably measurable from company filings. The commercial opportunity is better assessed through hospital demand, product availability, reimbursement-neutral procurement, and the ability to secure institutional contracts.

The most defensible opportunities are:

1. A reliable generic supply of conventional strengths.
2. Preservative-free unit-dose products.
3. Prefilled syringes for emergency and procedural use.
4. Premixed infusion products.
5. Products designed for shortage-prone strengths or package sizes.
6. Contract manufacturing and private-label supply.
7. Specialty delivery systems supported by new clinical data.

A branded injectable launch without a workflow or supply advantage would face weak pricing power. A differentiated product with a defensible patent estate could capture greater value, but development costs and clinical requirements would be substantially higher.

How strong is the Ketalar patent estate?

The Ketalar patent estate is weak for conventional injectable use because the active ingredient, basic formulation, and core route of administration are long established. The stronger intellectual-property positions are available only through new technical features or clinical applications.

IP category	Strength for conventional Ketalar	Opportunity for new entrants
Composition of matter	None	None
Basic injectable formulation	Low	Limited
Preservative-free formulation	Potentially moderate if technically distinctive	Moderate
Prefilled syringe or premix	Potentially moderate	Moderate
Novel excipient combination	Case-specific	Moderate
New delivery route	Potentially strong	Higher development risk
Method of use	Depends on claim scope	Potentially strong
Manufacturing process	Narrow but useful	Moderate
Device combination	Potentially strong	Moderate to high

Key Takeaways

• Ketalar is an old ketamine hydrochloride injection with no meaningful current core patent barrier.
• The labeled formulation uses benzethonium chloride as a preservative, water for injection, and hydrochloric acid for pH adjustment.
• Conventional generic competition is established and price pressure is likely to remain high.
• The best excipient opportunities involve preservative-free, ready-to-use, premixed, or container-compatible presentations.
• A 505(j) ANDA is generally appropriate for a conventional generic injection; a differentiated formulation may require a 505(b)(2) application.
• Ketamine’s Schedule III status and sterile manufacturing requirements remain meaningful operational barriers.
• New patents are more likely to arise from delivery systems, formulations, devices, manufacturing processes, or method-of-use claims than from the basic injection.
• Ketalar-specific revenue is not separately disclosed by Pfizer.
• Commercial success will depend primarily on supply reliability, presentation, institutional contracting, and regulatory execution.

FAQs

Is benzethonium chloride required in every ketamine injection?

No. Benzethonium chloride is part of the labeled Ketalar formulation, but generic and new ketamine products may use different preservative strategies if approved by FDA.

Can a preservative-free ketamine injection receive patent protection?

Yes, but the claims must cover a technically distinctive formulation, manufacturing process, container system, or use. Simply removing the preservative may not provide sufficient novelty or non-obviousness.

Is Ketalar eligible for generic substitution?

Conventional generic ketamine hydrochloride injections may be therapeutically substitutable under applicable state and institutional rules when FDA-rated as therapeutically equivalent to the reference product.

Does Spravato compete directly with Ketalar?

No. Spravato contains esketamine and is administered as a nasal spray under a separate FDA-approved product and clinical framework. Ketalar contains racemic ketamine hydrochloride and is primarily an injectable product.

Can a company launch a new ketamine formulation without challenging a Ketalar patent?

Usually yes for a conventional product because Ketalar has no material current patent barrier. A later ketamine product, formulation, device, or method-of-use patent may create separate freedom-to-operate issues.

References

1. U.S. Food and Drug Administration. (2024). Ketalar (ketamine hydrochloride injection) prescribing information. Pfizer/Hospira.

2. U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: Orange Book. NDA 016812.

3. U.S. Food and Drug Administration. (2024). Spravato (esketamine hydrochloride) nasal spray prescribing information. Janssen Pharmaceuticals.

4. U.S. Food and Drug Administration. (2025). Drug shortages: Ketamine hydrochloride injection. Center for Drug Evaluation and Research.

5. U.S. Drug Enforcement Administration. (2024). Controlled substances schedules. U.S. Department of Justice.